This project includes the quantitative analysis of eicosanoids and "platelet activating factor" (PAF) from in vitro and in vivo experimental preparations. The accurate purification and quantification of PAF and eicosanoids released in vivo into sheep lung lymph and bronchoalveolar lavage fluid following exposure of animals to endotoxin, hyperoxia or thoracic radiation are necessary to Section III, Projects A, B and C. Included within this project are the development of highly sophisticated analytic techniques which will allow us to accurately quantify eicosanoids, PAF and new mediators as they are identified. These studies will help to define the role of lipid mediators in a variety of lung injuries and help to formulate logical and efficacious methods for the future study and therapy of diffuse lung injury.